RBAC : use exact names of roles in docs

1)https://www.couchbaseinc.acct.us.onehippo.com/developers/documentation/server/5.0/security/concepts-rba-for-apps.html

a) specify the role names exactly (like reserved/key words) in the docs. For ex: "query_select"  instead of "Query Select"

b) explain the format of the entries in the 'resources' column. For ex: what does "Bucket [ bucket-name ]: Docs"  or "N1QL: Index" mean?

c) give examples of using these roles, or point to corresponding pages.

2) https://www.couchbaseinc.acct.us.onehippo.com/developers/documentation/server/5.0/cli/cbcli/user-manage.html

a) Verify examples are working, and copy the output/result of running the CLI.

3) document any changes related to MB-24319 and MB-24315